diff --git a/src/pkg/os/signal/mkunix.sh b/src/pkg/os/signal/mkunix.sh
index e1ea66059b4..653b0166416 100755
--- a/src/pkg/os/signal/mkunix.sh
+++ b/src/pkg/os/signal/mkunix.sh
@@ -19,6 +19,6 @@ var _ = syscall.Syscall  // in case there are zero signals
 const (
 EOH
 
-sed -n 's/^[ 	]*\(SIG[A-Z0-9][A-Z0-9]*\).*/  \1 = UnixSignal(syscall.\1)/p' "$1"
+sed -n 's/^[ 	]*\(SIG[A-Z0-9][A-Z0-9]*\)[ 	].*/  \1 = UnixSignal(syscall.\1)/p' "$1"
 
 echo ")"